The mechanisms that cause glaucoma are not completely known. It is known that glaucoma results in abnormally high pressure in the eye, which leads to optic nerve damage. Over time, the increased pressure can cause damage to the optic nerve, which can lead to blindness. Treatment strategies have focused on keeping the intraocular pressure down in order to preserve as much vision as possible over the remainder of the patient's life.
Pursuant to such strategies, one or more implants can be delivered into the eye for shunting fluid out of the anterior chamber in order to regulate pressure in the eye. Accurate placement of an implant in the angle of the eye is critical for the targeted effect of reducing intraocular pressure (IOP). Placing an implant too distally into the eye, such as too distally into the supraciliary space, may leave no portion of the implant remaining in the anterior chamber. This may inhibit aqueous outflow, as the fluid will not have a direct communication with the flow target location if there is no opening to the anterior chamber.
Conversely if the implant is placed too proximally in the supraciliary space such that a significant portion of the implant remains in the anterior chamber, damage to the corneal endothelium may result from implants that protrude upwards and touch the cornea. Implants placed too proximally may also touch the iris resulting in increased amounts of pigment dispersion in the eye, which can increase outflow resistance and intraocular pressure by clogging the trabecular meshwork. Correct placement of the implant is desired for a safety and a successful surgical outcome.
Many surgical procedures in ophthalmology require visualization of the iridocorneal angle (sometimes referred to as “the angle”) of the eye. Current techniques include endoscopy and gonioscopy, though both require clinicians to use at least two hands during surgery. This can be cumbersome for the surgeon. Surgical procedures that primarily involve the measurement of the depth of the angle, such as many minimally invasive glaucoma surgeries (MIGS), may benefit from a simplified method of placing implants in the angle of the eye particularly with respect to visualization of the iridocorneal angle.
Proper placement of ophthalmic implants in the angle of the eye can be critical to implant performance. Current visualization techniques may provide satisfactory angle visualization, although current techniques suffer from a multitude of issues. Gonioscopy requires the clinician to use an additional hand during surgery and the gonio lens must be placed directly on the cornea, increasing risk of infection and corneal damage. The surgical microscope used during gonioscopy may also require adjustment for proper angle visualization, which adds to surgery time. Endoscopy also requires the clinician to use an additional hand during surgery and a may involve a larger or second limbal incision for access to the anterior chamber, increasing the potential for surgical complications such as hypotony. Additionally, these techniques are not intuitive to many physicians and require significant training.
In view of the foregoing, there is a need for direct visualization (DV) systems which are configured and adapted for measuring a depth of the iridocorneal angle of the eye. In addition, there is a need for the DV systems to deploy into the eye and be used with minimal trauma to ocular tissues.